Microfabrication of Custom Collagen Structures Capable of Guiding Cell Morphology and Alignment.

The patterning of biological components into structural analogues of native tissues to simulate an environment for directing cell growth is one important strategy in biomaterials fabrication. It is widely accepted that chemical, mechanical, and topological cues from the extracellular matrix (ECM) provide important signals for guiding cells to exhibit characteristic polarity, orientation, and morphology. To fully understand the delicate relationship between cell behavior and ECM features, biomaterials fabrication requires improved techniques for tailoring nano/microstructured patterns from relevant biological building blocks rather than using nonbiological materials. Here we reveal a unique approach for the nano/microfabrication of custom patterned biomaterials using collagen as the sole building material. With this new fabrication technique, we further revealed that custom collagen patterns could direct the orientation and morphology of fibroblast growth as a function of vertex density and pattern spacing. Our findings suggest that this technique may be readily adopted for the free form fabrication of custom cell scaffolds purely from natural biological molecules including collagen, among other relevant ECM components.

Virus-based surface patterning of biological molecules, probes, and inorganic materials.

An essential requirement for continued technological advancement in many areas of biology, physics, chemistry, and materials science is the growing need to generate custom patterned materials. Building from recent achievements in the site-specific modification of virus for covalent surface tethering, we show in this work that stable 2D virus patterns can be generated in custom geometries over large area glass surfaces to yield templates of biological, biochemical, and inorganic materials in high density. As a nanomaterial building block, filamentous viruses have been extensively used in recent years to produce materials with interesting properties, owing to their ease of genetic and chemical modification. By utilizing un-natural amino acids generated at specific locations on the filamentous fd bacteriophage protein coat, surface immobilization is carried out on APTES patterned glass resulting in precise geometries of covalently linked virus material. This technique facilitated the surface display of a high density of virus that were labeled with biomolecules, fluorescent probes, and gold nanoparticles, thereby opening the possibility of integrating virus as functional components for surface engineering.

Responsive 3D microstructures from virus building blocks.

Fabrication of 3D biological structures reveals dynamic response to external stimuli. A liquid-crystalline bridge extrusion technique is used to generate 3D structures allowing the capture of Rayleigh-like instabilities, facilitating customization of smooth, helical, or undulating periodic surface textures. By integrating intrinsic biochemical functionality and synthetic components into controlled structures, this strategy offers a new form of adaptable materials.